The disclosed embodiments of the present invention relate to an antenna design, and more particularly, to an antenna tuning circuit for setting an antenna resonant mode of a multi-port antenna structure and a related antenna tuning method thereof.
The growth of the usage of mobile internet and multimedia services has been explosive in recent years. With the enriched features and services available to the end users, the mobile devices, including smart phones, tablets, wearable devices, etc., are required to support higher data rates promised by 3G (third generation), 4G (fourth generation) or more advanced communication standard with backward compatibility of the legacy 2G (second generation) communication standard. In the meantime, a combination of different frequency bands will need to be supported. Consequently, the increase in complexity of the mobile devices leads to greater challenges and more stringent requirements on the front-end design and the antenna design. To achieve reduced cost and chip area, a multimode multiband (MMMB) solution is proposed for supporting multiple air interface standards while covering multiple frequency bands. However, concerning a slim mobile device with a metal housing, the design difficulty of an antenna used in the MMMB environment is raised. Thus, there is a need for an adaptive antenna solution which is capable of meeting the MMMB requirement of a slim mobile device.